2011 Prius - Knocking

Discussion in 'Gen 3 Prius Main Forum' started by savemyprius100, Sep 25, 2025 at 8:37 AM.

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  1. savemyprius100

    savemyprius100 New Member

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    Greetings PRIUSchat,
    I have a 2011 Prius with ~180k miles on it and have been experiencing engine knocking all year. My coolant level drops and I have pressure tested it many times and there appear to be no leaks. I'm worried about the head gasket . . . or should I be worried about the EGR valve being an issue?

    Can you guys suggest the best way to try and attack this 3rd gen engine knocking issue? Other than the occasional knocking, the car runs great, but the knocking is starting to become much more frequent at start up/recharge.

    Cleared the check engine light a few times but it comes back on after some time, few codes that show misfire in a few cylinders.

    Thank you all & God Bless
     
    #1 savemyprius100, Sep 25, 2025 at 8:37 AM
  2. JC91006

    JC91006 Senior Member

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    Your fear of the head gasket has just shown it's true form. You'll need to replace the head gasket or get yourself another engine. No other real solution
     
    #2 JC91006, Sep 25, 2025 at 10:20 AM
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  3. ASRDogman

    ASRDogman Senior Member

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    Did you use a bore scope to see the coolant leaking into the cylinders?
    It doesn't take a lot for the engine to knock.....

    Sounds like the head gasket is leaking... it will only get worst. The longer you wait the more it will
    likely cost you....

     
    #3 ASRDogman, Sep 25, 2025 at 1:36 PM
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